A tracheotomy is a medical procedure for patients requiring mechanical ventilation in which an opening is created through the neck into the trachea creating a stoma or tracheostomy. A tracheostomy tube, comprised of an inner cannula within an outer cannula, is placed into the stoma and connected by an elbow adaptor through a breathing circuit to the ventilator. Nearly 100,000 tracheostomies are performed in the US annually. Many patients with tracheostomies are ventilator dependent, tetraplegic patients with compromised lung capacity and are unable to fix any ventilator disconnections or other airflow disruptions on their own leaving them with as little as two minutes to live without ventilation.
The current “gold standard” devices typically employ friction fit connections in the ventilator circuit, a clip connection between the cannulas, and a Velcro securement between the tracheostomy tube and the patient's neck. These connections are designed for quick attachment, but are prone to frequent unintended disconnections. A tracheostomy tube and ventilator circuit less prone to unintended ventilator disconnections can provide the necessary safety measures to prevent these catastrophic events.
Our task was to design, fabricate, and validate a system that would minimize unintended airflow disruptions of the ventilator circuit, thereby increasing safety, comfort, and peace-of-mind for the patient. The resulting prototype, described herein, may include one or more of: a Bayonet Neill-Concelman (“BNC”) type connection for the inner cannula to elbow adaptor connection, a threaded connection for the inner cannula to outer cannula connection, and a pressure relief valve as a part of the elbow adaptor. This combination of elements may be important as they have surprisingly beneficial effects in combination. For example, the BNC connection improves strength of the connection and confirms correct assembly, particularly in combination with the threaded connection to improve usability and reduces force into the stoma. The pressure relief valve helps mitigate high airway pressures that may cause disconnections or lung damage.
Verification and validation testing demonstrated that the initial prototypes described herein fulfilled all requirements tested except compatibility with current art, weight of the current design, and air pressure tolerance. Of particularly significance was the surprisingly enhanced ease of use and reliability. The prototypes described herein took the same amount of time to assemble and disassemble by both care providers and untrained lay people; users made more assembly errors with currently available commercial devices compared to the devices described herein.